Asset Quality - Consumer Credit Exposure (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 112,390	$ 101,854
Accrued interest	233	198
Total consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	6,431	13,637
Two years prior	13,208	5,890
Three years prior	5,277	2,095
Four years prior	1,732	432
Five years prior	348	384
Prior	2,746	2,812
Revolving Loans Amortized Cost Basis	5,095	5,156
Revolving Loans Converted to Term Loans Amortized Cost Basis	572	612
Total	35,409	31,018
Accrued interest	81	85
Total consumer loans | Real estate — residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	4,711	9,636
Two years prior	9,427	3,274
Three years prior	3,023	966
Four years prior	802	140
Five years prior	114	163
Prior	1,510	1,576
Revolving Loans Amortized Cost Basis	1	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	19,588	15,756
Total consumer loans | Real estate — residential mortgage | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	3,552	7,906
Two years prior	8,267	2,909
Three years prior	2,691	777
Four years prior	668	84
Five years prior	65	126
Prior	1,063	1,096
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	16,306	12,898
Total consumer loans | Real estate — residential mortgage | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	1,094	1,686
Two years prior	1,125	351
Three years prior	314	169
Four years prior	119	39
Five years prior	32	25
Prior	277	308
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	2,961	2,578
Total consumer loans | Real estate — residential mortgage | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	14	26
Two years prior	34	14
Three years prior	18	19
Four years prior	14	16
Five years prior	16	9
Prior	141	142
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	237	226
Total consumer loans | Real estate — residential mortgage | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	51	18
Two years prior	1	0
Three years prior	0	1
Four years prior	1	1
Five years prior	1	3
Prior	29	30
Revolving Loans Amortized Cost Basis	1	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	84	54
Total consumer loans | Home equity loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	220	1,472
Two years prior	1,355	1,119
Three years prior	1,021	382
Four years prior	332	153
Five years prior	127	181
Prior	983	964
Revolving Loans Amortized Cost Basis	3,524	3,584
Revolving Loans Converted to Term Loans Amortized Cost Basis	572	612
Total	8,134	8,467
Total consumer loans | Home equity loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	136	1,051
Two years prior	999	830
Three years prior	773	251
Four years prior	224	96
Five years prior	80	128
Prior	686	666
Revolving Loans Amortized Cost Basis	2,248	2,244
Revolving Loans Converted to Term Loans Amortized Cost Basis	401	423
Total	5,547	5,689
Total consumer loans | Home equity loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	77	394
Two years prior	327	263
Three years prior	226	111
Four years prior	88	44
Five years prior	36	40
Prior	205	204
Revolving Loans Amortized Cost Basis	969	1,004
Revolving Loans Converted to Term Loans Amortized Cost Basis	131	143
Total	2,059	2,203
Total consumer loans | Home equity loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	7	27
Two years prior	29	24
Three years prior	21	20
Four years prior	20	13
Five years prior	11	13
Prior	90	92
Revolving Loans Amortized Cost Basis	304	333
Revolving Loans Converted to Term Loans Amortized Cost Basis	40	46
Total	522	568
Total consumer loans | Home equity loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	2
Three years prior	1	0
Four years prior	0	0
Five years prior	0	0
Prior	2	2
Revolving Loans Amortized Cost Basis	3	3
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	6	7
Total consumer loans | Consumer direct loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	1,500	2,524
Two years prior	2,423	1,497
Three years prior	1,233	747
Four years prior	598	139
Five years prior	107	40
Prior	201	207
Revolving Loans Amortized Cost Basis	603	599
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	6,665	5,753
Total consumer loans | Consumer direct loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	1,062	1,799
Two years prior	1,817	1,129
Three years prior	925	517
Four years prior	415	65
Five years prior	51	17
Prior	116	129
Revolving Loans Amortized Cost Basis	104	109
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	4,490	3,765
Total consumer loans | Consumer direct loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	369	612
Two years prior	501	295
Three years prior	247	174
Four years prior	138	46
Five years prior	34	10
Prior	47	45
Revolving Loans Amortized Cost Basis	203	212
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	1,539	1,394
Total consumer loans | Consumer direct loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	24	45
Two years prior	59	33
Three years prior	31	27
Four years prior	23	11
Five years prior	7	3
Prior	11	12
Revolving Loans Amortized Cost Basis	54	60
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	209	191
Total consumer loans | Consumer direct loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	45	68
Two years prior	46	40
Three years prior	30	29
Four years prior	22	17
Five years prior	15	10
Prior	27	21
Revolving Loans Amortized Cost Basis	242	218
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	427	403
Total consumer loans | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	967	972
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	967	972
Total consumer loans | Credit cards | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	496	500
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	496	500
Total consumer loans | Credit cards | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	383	387
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	383	387
Total consumer loans | Credit cards | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	87	84
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	87	84
Total consumer loans | Credit cards | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	1	1
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	1	1
Total consumer loans | Consumer indirect loans
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	5
Two years prior	3	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	52	65
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	55	70
Total consumer loans | Consumer indirect loans | 750 and above
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	5
Two years prior	3	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	24	30
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	27	35
Total consumer loans | Consumer indirect loans | 660 to 749
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	20	26
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	20	26
Total consumer loans | Consumer indirect loans | Less than 660
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	8	9
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	8	9
Total consumer loans | Consumer indirect loans | No Score
Financing Receivable, Credit Quality Indicator [Line Items]
One year prior	0	0
Two years prior	0	0
Three years prior	0	0
Four years prior	0	0
Five years prior	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0	0
Total	$ 0	$ 0